Nonpharmacologic treatments for chronic low back pain are now recommended as the first line of therapy according to several US-based clinical guidelines. One recommended treatment is mindfulness-based stress reduction (MBSR) because its benefits are supported by evidence of moderate quality in a recent systematic review. MBSR has received much public and media attention, but the potential for its widespread implementation is unknown. Learning the classic MBSR program, which has three core practices of a body scan, mindful yoga and mindfulness meditation, makes heavy demands on patients' time. To optimize the reach of MBSR, we need to know if it can be packaged to be attractive and feasible to patients. In this project, we directly evaluate MBSR optimization using the domain of Intervention Characteristics from the Consolidated Framework for Implementation Research (CFIR) to create eight video vignettes. These vignettes will describe versions of MBSR that differ according to characteristics such as relative advantage, adaptability and complexity. We will conduct a 23 web-based factorial-design experiment. We will recruit 400 patients with chronic low back pain as participants. All will view a video vignette about classic MBSR and then be randomized to one of the eight versions of MBSR. They will view a corresponding video vignette of the new version of MBSR (unless they have been assigned to classic MBSR). Participants will then be asked to complete a survey developed using the Theory of Planned Behavior to collect information on the attractiveness of the MBSR vignette(s) they observed and their own back pain history, current clinical status, and other characteristics. We will conduct multiple regression analyses on the survey data to characterize the subpopulation of patients who are likely to engage in classic MBSR and determine the core components that are most important to them. Using structural equation analysis, we will also compare the differential influence of attitudes, subjective norms, and perceived behavioral control (from the Theory of Planned Behavior) on the likelihood of use of classic MBSR. Finally, we will use structural equation analysis to explore whether the MBSR characteristics that we varied in the vignettes increase participants' behavioral intentions to engage in MBSR and its core components. The product of this project will be actionable information regarding the subpopulation for whom MBSR is a good fit and characteristics of the intervention that require repackaging or reframing to optimize fit and increase its reach. Such information is foundational for optimizing the likelihood that MBSR will be considered by patients as a viable treatment for chronic low back pain. Once these dissemination questions are answered, we can compare classic MBSR with the modified version (based on the results of this study) in an effectiveness-implementation hybrid study that attends to other critical domains of the CFIR.